“My question is: How is the F-35's cockpit better than the F/A-18E/Fs, and why did we even make the improvement?
Also, the F-35 has 55 buttons on its HOTAS system. Why does it have so many HOTAS-bound buttons when earlier jets like the aforementioned Super Hornet have less?”
You’re looking at the evolution of 60 years worth of cockpit design in these photographs, not to mention 60 years of evolution in fighter aircraft design, missions systems, and capabilities. One thing that is clearly visible in all of these photographs is the trending from the pilot as a stick and rudder guy to more of a weapon systems officer and a tactician. That is, cockpits and missions systems aboard modern fighter aircraft are handling much, much more of a routine and mundane aspects of flying an airplane and allowing the pilot to concentrate much more of his brain power on employing weapons, operating mission systems and concentration on the battle. In contrast, the jet and the computer hardware and software aboard are handling most of the aspects of flying the aircraft and translating all sensory influence and systems information. It can then display this onto easy to read, and understand, minimalist cockpit displays, which the pilot can call up and can set however he desires when is needed for a particular stage of a flight or mission.
As visible in a 1960s era F-4 cockpit, were computer power technology is nowhere near what it is today, all you could do was display the information, either on analog gauges or crude, monochrome CRT displays. The pilot would have to digest that information and make decisions accordingly. Combat experiences in Vietnam showed that there was only so much brain power. A fighter pilot could be called up under stress and in combat to use. Excessive amounts of systems with simply saturate the individuals, and potentially cause them to overlook critical elements of the fight that could kill them. General Robin Olds once commented that when they fenced in in Vietnam, i.e. crossing over in the enemy territory, that they actually started turning systems off in the F4 because they did more harm than good, and it allowed the pilot to concentrate on the battle better.
The F-18 cockpit is a classic example of lessons learned from the Vietnam conflict. Here computers have made considerable improvements in information crunching and can be used to handle many more tasks aboard. Other technologies, such as multi function displays, head-up displays and HOTAS controllers (a Hornet has about 40 or so buttons on the stick and throttle) helped digest more information and allow the pilot to better command the aircraft and its mission systems with his head out of the cockpit for better SA. Take this one step further with the F-35 cockpit combined with blazing fast computers, all glass touchscreen displays, HMDs, encrypted networking between other friendly assets in the battle space and the aircrews have far more systems and capabilities with much more brainpower available to use them. About 95% of the F-35 pilot’s activity in the cockpit can be concentrated on where he is and other assets are, where the enemy is, what threats are out there, how they are going to coordinate, and use their combine force to destroy them, and what weapons he wants to employ to do so.